Seed Starting 101 - Part V

When it comes to seed starting, choosing the right planting medium can make a big difference in how efficiently your seeds and plants receive moisture, as well as how well the medium drains when watered.

Most of the ready-to-use seed starting mixes I've tried have one thing in common – they don't absorb water or drain well. Their light fluffy texture is easy on seeds, but seems to almost repel water. Granted, if you prefer to wet the medium first before sowing the seeds, it'll already be, well, wet. After it dries, however, you may start to see the lack of draining ability I spoke of.

As a result of this, I tend to mix a little compost with the seed starting mix. It seems to add some thickness and weight to it, and greatly helps it absorb water and drain better.

In this video, I do a simple experiment to compare water absorption and drainage. In one container, I fill it with only ready-to-use seed starting medium. In the other, I mixed the same seed starting medium with compost, in a 1 part compost to 3 parts seed starting mix ratio.

The first step tests water absorption by pouring water on the top of each mix, as though you were watering your seedlings this way. Eventually, drainage is tested, by continuing to add water to each container.

After you try it, show it off to other members in thegardener's gallery.Post your photos